electron multiplier: recorder trace

Figure 7: The mass spectrum of osmium. This recorder trace was obtained with an electron multiplier detecting OsO3−. The leftmost and rightmost peaks were recorded with the detector gain set at a value 100 times that used for the rest of the spectrum; this change is marked by the change in the baseline position. The small satellite peaks to the left are those of the low abundance oxygen isotopes 17O and 18O; the osmium isotopes are, from left to right, 184Os, 186Os, 188Os, 189Os, 190Os, and the satellite peaks of 192Os.